What causes shallow constant pain in lower rib cage?

I have developed a constant shallow pain tender to the touch in my rt lower rib cage about 3-4 inches lateral of the sternum on the last few ribs not attached to sternum directly onset was a week ago roughly. The last few ribs on the bottom rt lower side. It just intensified dramatically a moment ago as i was putting in a earring and laughed while my rt arm was over my head in stretched position getting ready to go out. I spent most of the day today in bed with a heating pad resting and it felt better. My job requires some heavy lifting 75lb items. I moved about 10 of these items yesterday at work since the onset. I have done some heavy to moderate lifting prior to the onset as part of my daily work duties. It is soar to direct pressure currently and feels like I have a Knife stuck in my rib cage. I am a 37 year old female in good shape and weigh approximately 120 lbs. No fever or nausea or other symptoms and I have been taking alleve to help with pain. The pain lessens when im in a slightly leaned forward position seating or standing. Im thinking Ive strained a muscle or a intercostal cartilage between my ribs. What do u think....Thanks XXXXXXX
Asked by Me , 58 minutes ago
What is the estimated time before I receive a responce
Asked by Me , 26 minutes ago

Brief Answer:
Muscle spasm. Little work up for gallbladder
Detailed Answer:
Good day Miss XXXX!
Thank you for asking. My name is Dr S Khan and i would like to help you with your right hypochondriac pains sudden in onset with a history of heavy lifting objects.
Miss XXXXXXX This pain most probably looks like a muscle spasm which has been a result of your spraining activities recently so i advise to stop weighing 70lbs things when you yourself are hardly 120. If that is true and the issue is because of muscle spasm then all you would need is some acetaminophen and some skeletal muscle relaxants like tizanidine or orphenadrines with some rest with future avoidance of these heavy lifting labours.
But to be on the safer road lets do some work up. Such pains in women of your age are also very common because of the gallbladder issues with stones and reflux. SO i recommend i Simple abdominal ultrasound with liver functions and pancreatic profile assessment to rule out hepatobiliary tract which lso presents in the very same pattern.
Hope this answer finds you in good faith Miss XXXXXXX If you have any more queries please feel free to ask , i would love to answer and keep me posted about your updates.
Take some very good care of yourself and Kindly close the discussion and rate the answer as per your experience.
Regards
D S Khan